Fluid pressure variable pitch fan control



Aug. 8, 1950 E. J. SANDERS 1 FLUID PRESSURE VARIABLE PITCH FAN CONTROL Filed June 11, 1948 3 Sheets-Sheet 1 JNVENTOR. E/more J. Jcmde/v ATTORNEY 1950 E. J. SANDERS 2,517,932

FLUID PRESSURE VARIABLE PITCH FAN CONTROL Filed June 11, 1948 I5 Sheets-Sheet 2 a p a; 3. h

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f/more J. Sande/:5

' BY @101 w. QM

1950 E. J. SANDERS 2,517,932

FLUID PRESSURE VARIABLE PITCH FAN CONTROL Filed June 11, 1948 3 Sheets-Sheet 3 73 PE 551? VO/R IN VEN TOR. E/mare J. Sande/:5

WMWMM A T'TOIFNE Y Patented Aug. 8, I 1950 FLUID PRESSURE VARIABLE riToHFA-N CONTRQLII tElmore J. Sanders, San GabrieL Galif assig-nor to Evans Products-Company, Plymouth, Mich., a corporation of Delaware I Application June 11, 1948,-SerialNo. 32,291

l-his invention relates to engines equipped with variable pitch fan blade assemblies, which are adapted to vary thevolume of air supplied for engine coolant temperature control, in which -'the air-flow can be directed toward oraway from the engine radiator as required, and an object is to produce a new and improved mechanism for supplying fluid under pressure to an expansible-chamber motor operatively connected to the variable pitch fan blade assembly and thermostatically regulating I the [pressure of the fluid delivered to the motor.

Another object is to control the operation of a Other objects and advantages of the inven-- tion will hereinafter appear and for purposes of illustration but not of limitation, embodiments of the invention are shown on the accompanying drawings, in which: I

Figure 1 is a fragmentary schematic view of a portion of an internal combustion engine equipped with a variable pitch fanblade assembly, a portion of the liquid cooling jacket being broken away to show the thermostatic element;

Figure 2 is an enlarged vertical sectionalj elevation ofgthe variable pitchfan blade assembly, expansible chamber-motor, engine water pump and associated parts ;I

12 Claims. (01. 123 -1975) internal combustion Figure 3 is a sectional view substantially on the line 3-3 of Figurez; I

Figure 4 is an enlarged sectional view showing the thermallyflresponsive fluid pressure .reg ulat in g mechanism; and I Figure 5 i a fragmentary sectional view shows ing an alternate form in which the water pump impeller is disposed within the engine block.

The "illustratedembodiment of the invention shown on Figures 1 to 4 comprises an internal combustion engine "Ill having ,a water cooling jacket H (through which liquid, such as watenis adapted to be forced by ,a pump having ajcasing l2 .lsuitablyconnected to an end wall of the engine 10, Within the casing is a rotary impeller 113 of the bladetype forcausing liquid circulation though the engine jacket. Tubes M and I5 lead fromopposite portions of the pump casing .and .communicatecwith the upper and lower portions of the engine cooli g jacket as will be'readily understood.

Secured inrany :suitable manner to the front end of the pump casing i2 and forming a wall ithereof is a bearing housing It having a water pump filler opening Zita closed by a plug IEb. Mounted within the housing it is a shaft 11, an intermediate portion of which is supported by a ball bearing unit it. On the forward end of the shaftis keyed the hub of a drive sheave it, which is suitably grooved to receive v belts 20. The belts 52B arev also connected to sheaves (not shown) driven in any suitable manner by the internal combustion engine It. Interposed between the hub of the sheave l9 and the forward end portion of the bearing housing it is a ball bearing unit 321, a spacer sleeve 22 being inter- ;posed between tghe ball bearing units l8 and 2|. It ,will be observed that the right-hand portion =(Figure 2') of the sheave l9 isrecessed to receive the end portion .of :the bearing housing Hi to economize on space and compact the assembly.

The forward-or '1eft-hand face (Figure 2) of the sheave i 9 is cupped to provide a chamber 23 for the expansible chamber motor, and forming an end wall for the chamber 23 is a diaphragm 24 of .rubber-likematerial, the edge portions of which are securely held between a pair ofmetallic rings 25, the central portions of which are ribbed as indicated at 23, securely to hold the diaphragm in place. An end member 27 is suitably secured, as by bolts, to-ithe sheave IQ thereby rigidly to 'anchor the peripheral portion of the diaphragm in place and form a liquidtightjoint. Preferably the end member 21 is in two sections suitably bolted together to retain therebetweenthe variable pitch ian blade assembly, generaliy indicated tit-28. The specific structure of the fan blade assembly forms no part of the present invention andreference is hereby made to the patent to Earley :et-allNo. 2,437,810, dated March-l6, 1948, for a more complete description of the structure-and operation. Suflice it to Say that a-piurality'of fan blades 29 is provided ;and each fan blade has a stub'shaft rotating :in a ball bearing unit 31. Engaging the innerend of the ball-bearing unit M is a nut 32 and pinned to the lreducedrend of the stub shaft 30 is a: discett having an eccentrically positioned actuating pin 134,-, which engages in a shoe 35. The srhccfifi seatstina groove in'a'carrier 36 which i secured, as by welding, to a cup 3"! which is secured to the central portion of the diaphragm 24, a lug 38 passing through an aperture in the center of the diaphragm and a plate 39 being secured to the opposite side of the diaphragm. The lug is upset to secure the plate 39 in clamping relation. The arrangement is such that movement of the cup 31 to the left of Figure 2 imparts conjoint movement to the several fan blades 29, and movement of the cup in the opposite direction is effected by a conical spring 46, which bears at one end against the carrier 35 and at the opposite end against a plate 4|, suitably fixed as by bolts to the outer face of the end member 21.

Preferably the fan blades 29 are counterweighted so that they are constantly urged into maximum pitch. Accordingly in the event of failure in the operation of the mechanism for varying the fan blade pitch, the blades will be in maximum pitch to supply cooling air t th ternal combustion engine.

A nut 42 on the end portion of the shaft l1 clamps, a washer 43 against the outer surface of the hub of the sheave I9 and the water pump impeller i3 is fixed to the opposite end of the shaft 11 for rotation therewith. The shaft 11 is provided with a longitudinally extending, axially disposed conduit 44 which opens at its left-hand end (Figure 2) into the chamber 23, the opposite end communicating with a lateral passage 45 to which a tube 48 is connected. As will hereinafter appear, liquid under pressure from the tube 45 passes through the lateral passage 45 into the bolt conduit or passage 44 and thence into the chamber 23 to exert pressure against the diaphragm 24 for varying the pitch of the fan blades 29. It will be apparent that the righthand end portion (Figure 2) of the shaft H extends into the water pump casing I2. According- 131, it is necessary to effect a, liquid seal between opposite sides of the hub of the water pump impeller i3 and the water pump casing on the one hand, and the bearing housing [6 on the other hand. .This is accomplished by a fluid seal 41. e

The structure of the fluid seal 41' isas follows: A metallic ring 48 is secured to the hearing housing i and surrounds the shaft l-l. Bearingagainst the flat outer face of the ring 48 is a carbon ring 49 which has an outwardly projecting. relatively narrow rib in sliding contact with the ring 48. A rubber bellows 50 is connected at one end to the opposite face of the carbon ring-59 and has its opposite end bonded to a metal cage 5!, which is fiangedto provide a seat for one end of a, coil spring 52, the opposite end of which bears against the hub of the water pump impeller l3. The pressure of the fluid on opposite sides cooperates with the above'parts efiectively to prevent the water from within the water pump casing l2 and liquid, such as oil, for th passage 44, from intermingling. Adjacent the fluid seal is a drain cavity 53.

A similar fluid seal 54 is interposed between the opposite face of the hub of the pump impeller l3 and the adjacent portion of the casing 12, this seal also employing a similar car- -bon ring 55 which is spring-urged against la metal ring 56 by a coil spring, a rubber bellows and metallic cage being similarly employed.

Intermediate the metallic ring 56 and adjacent wall of the casing I2 is a rubber-ring-H; which is forced into fluid-tight sealing engagement by the pressure exerted bythe carbon ring r through the ring 56. It will also appear in this form of the fluid seal that a rubber ring 58 is urged by the metallic cage against the impeller hub effectively to seal that region. Fluid-tight seals of the bove character are available on the market and their detail construction and operation are well-known to'those skilled in this art, so that further description thereof is not deemed necessary.

The tube 46 may lead to the engine oil pump (not shown) so that oil under pressure is normally forced through the tube 46 and into the chamber 25 for actuating the expansible chamber motor. As will hereinafter appear, the pressure of oil delivered to the expansible chamber motor is thermostatically controlled as, for ex ample, in accordance with the temperature of the water or other liquid in the engine cooling system. In this manner, when the engine is relatively cold, the fanblades .29 may be disposed at zero,.minimum or reverse pitch, thus reducing or shutting off the air supplied for engine coolant temperature control. As the temperature of. the liquid in the engine cooling jacket increases so that cooling action of the fan is desired, then the oil pressure is utilized automatically to vary the pitch of the fan blades gradually to increase the volume of air supplied for engine cooling purposes.

As shown, a valve housing 59 interposed in the tube line 46 is attached to the engine cooling nected for actuation by the thermostat 60 is a rod 62 which has a reduced extension 63 providing a shoulder against which a flanged washer 64 abuts. Thermostats suitable for this purpose are commerically available and involve the .use of materials sensitive to temperature variations for effecting positive to and fro movement of therod 62, increase of temperature causing the rod 62 to move upwardly (Figure 4) and reduction in temperature causing the rod to move downwardly.

Connected to a side of the valve casing 59 is a tube 65, which leads to the engine crank case (not shown) or other suitable reservoir. Having one end seated against the flanged washer 64 is a coil spring 66, the opposite end of which engages a shoulder on a piston type valve member .61, slidable on the reduced extension 63, a pin 68 limiting the outward movement of the valve 61. In the normal position, the valve 61 engages a ported ring 69. A relatively stronger coil spring 'Til. seats at one end against a disc 1| which engages a shoulder 12 on the rod 62 and the 0pposite end engages a ring I3 which abuts against a shoulder on the valve casing. When the rod 62 moves upwardly, it first compresses the coil spring!!! but after the valve 61 engages its seat 74, further movement of the rod 62 will additionally compress the lighter spring 66. When the temperature of the cooling liquid decreases, the coil springs 19 and 66 successively operate to unseat the valve, as will be readily apparent.

In operation, when the engine is cold, liquid from the oil pump will be forced through the valve casing 59, the ported ring 69 and to the reservoir or crank case through the tube65. When the temperature of the engine cooling liquid increases, a pressure differential is created by the closing or partial closing of the valve 61 s th t -.e;-sraesa gliigher fiui'd-:-pressureszareibuiltiup in thefchamber 23 for .-.'actuat-ing the sdi'aphr-agm 2i! to' increase athe snitch. of-sthe'rfan blade. Thus: the .ioperation of; the expansible; chambersmotor is; controlled by the position of .jthe *valve 7.61 which ,in 'turn is iacc rd sly; he .zgrea-terlwill. bee hepressure developed in the expansible chamber motor, against :th flexible :d ar hsaemi .z li amortiQn or all Icy-passed to cran c sethro h-imman nt. z llcf nemes- Sure s r t 'bir th r ili-eumnma zbaut li edzin actuating ;thegdiaphriagm 24 against the tension of thecoil spring 40. In this manner, the pitch of the several ;=f a n:bla'desjiis smoothly and auto matic lly var ed n. acc rdancewiththe t mpera- *turerequireme'nts' oftlie engine.

An important feature of thisinven'tion resides in the manner inswhi'ch'liquid isldeiivered to the expansible chamber motor, as shown, the gliguid being passed coaxially of the water pum-p;.;im-

peller; directly to the ",expansible chamber motor. The fluid sealing of the pump impeller to militate against the oil entering the pump casing and on the other hand, preventing water from entering the oil stream, is of importance in effecting an exceedingly compact and eflicient design.

The form of the invention shown on Figure 5 is similar to that above described, except that the water pump impeller l3a is disposed within the engine cooling jacket Ha, a fluid seal 54a being interposed between the hub of the impeller [3a and a bearing housing l6 which abuts against and is suitably secured to the engine block. In this instance, the tube 46 delivering oil under pressure to a lateral passage 45a in the bearing housing It registers recurrently With a lateral passage in the driven shaft Ila. which communicates with an axial passage 44a. A fluid seal 41a. on the opposite side of the passage 45a. effectively seals the adjacent portion of the shaft against liquid.

It is to be understood that numerous changes in details of construction, arrangement and operation may be effected without departing from the spirit of the invention especially as defined in the appended claims. The thermally responsive unit may be located differently than above described, as, for example, it may be responsive to the lubricating oil temperature, other parts of the engine, or to the air temperature.

What I claim is: I

1. In an internal combustion engine equipped with a variable pitch fan blade assembly to supply air for engine cooling purposes, means responsive to the engine temperature for varying the pitch of the fan blades, said means comprising an expansible chamber motor having a movable wall operatively connected to the fan blade assembly, a water pump for the engine having an impeller coaxial with the fan blade assembly, a source of fluid under pressure in communication with said chamber through the axis of said impeller to actuate said motor, and valve means for regulating the pressure of the fluid in said chamber.

2. In an internal combustion engine equipped with a variable pitch fan blade assembly to supply air for engine cooling purposes, means responsive to the engine temperature for varying the pitch of the fan blades, said means comprising 'an expansiblerchamberrmotor valiaving amovable :wall operatively connected: to !-the cfan iblaideras- .sembly,':.a water :pumpiforalthe engine, said water pump and expansible chamber motor :being disposed between ithe :fan blade assemblysandithe iengine, :and'meansfor supplying fluid :underpressure through the water pump-toi-said r'motor to .slactuate same, and valve means ifor e'regulating the pressure of thefluid supplied L saidsmotor.

- 3. "The. organization as :claimed inuclaim 2,1'i11 @i'which' the water .pump, fan 1 blade assembly and expansi-ble chamber motor arecoaxially arranged,

and the :fiuidsupplying-means includes: a conduit leading .2170 the motor disposed .coaxially of" said :water pump. 1

' ".In an vinternalcombustion enginelequipped "with a variable pitch fan bladeassembly to supply .air :for engine cooling purposes, means responsive 3130 the engine temperature for svarying ithe-pitch-of the fan; blades, said means:.compris ing .anaexpansiblechamber motor havingsa-smovable Wall operatively connected touthe "fan blade .zassemioly, .axdrivefor the 'fan blade .assernb'lyfhaving alportionscooperating with gthe movable lvra'll to form .ithei-chamber :forthe :expansible chamber motor, a liquid cooling pump for the engine having a rotary impeller, a shaft coaxial with said drive and impeller and secured for rotation thereto, said shaft having a longitudinal passage opening into the chamber of said expansible chamber motor, a source of fluid under pressure in communication with said chamber through said passage, and means for regulating the pressure of fluid in said chamber.

5. The organization as claimed in claim 4, in which the shaft passage extends therethrough from end to end, and fluid sealing means for sealing the pump impeller for militating against intermingling of the cooling liquid and pressure fluid.

6. The organization as claimed in claim 4, in which the regulating means comprises a valve thermostatically responsive to the temperature of the engine cooling liquid.

7. The organization as claimed in claim 4, in which the regulating means comprises a by-pass for the fluid under pressure, valve means to control the flow of fluid through said by-pass, and thermostatic means responsive to the engine temperature for actuating said valve means.

8. In an internal combustion engine equipped with a variable pitch fan blade assembly to supply air for engine cooling purposes, means responsive to the engine temperature for varying the pitch of the fan blades, said means comprising an expansible chamber motor having a movable wall operatively connected to the fan blade assembly, a drive for the fan blade assembly having a portion cooperating with the movable Wall to form the chamber for the expansible chamber motor, a support carried by the engine for said motor, fan blade assembly and drive, a source of fluid pressure in communication with said chamber and including fluid passage means in said support, and valve means thermostatically responsive to the engine temperature for regulating the pressure of fluid in said chamber.

9. In an internal combustion engine equipped with a variable pitch fan blade assembly to supply air for engine cooling purposes, means responsive to the engine temperature for varying the pitch of the fan blades, said means comprising an expansible chamber motor having a movable wall operatively connected to the fan blade assembly, a water pump for the engine, said water pump and eXpansible chamber motor being disposed between the fan blade assembly and the engine, means forsupplying engine lubricating oil under pressure through the water pump to said motor to actuate same, and valve means for regulating the pressure of the lubricating oil supplied to said motor.

10. In an internal combustion engine equipped with a variable pitch fan blade assembly to sup- -ply air for engine cooling purposes, means responsive to the engine temperature for varying the pitchof the fan blades, said means comprising-an expansible. chamber motor having a movable wall operatively connected to the fan blade assembly, a water pump for the engine having.

cally responsive to the engine temperature for regulating the pressure of the lubricating oil in said chamber.

11. In an internal combustion engine equipped with a variable pitch fan blade assembly to sup-- ply air for engine cooling purposes, means resure in communication with said chamber, and

valve means for regulating the fluid in said chamber.

12. The organization as claimed in claim 11, in which the' drive for the fan blade comprises a pulley axially recessed to cooperate with the movable wall to provide the motor chamber.

ELMORE J. SANDERS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES. PATENTS Number Name Date 1,327,381 Furber Jan. 6, 1920 2,022,709 Embery et al Dec. 3, 1935 

